reviewed by: <aacid@kde.org>

        * glib/poppler-document.cc:
        * glib/poppler-document.h:
        * glib/poppler-page.cc:
        * glib/poppler-page.h:
        * glib/poppler-private.h:
        * glib/poppler.h:
        * poppler/Annot.cc:
        * poppler/Annot.h:
        * poppler/Catalog.cc:
        * poppler/Catalog.h:
        * poppler/CharCodeToUnicode.cc:
        * poppler/CharCodeToUnicode.h:
        * poppler/Dict.cc:
        * poppler/Dict.h:
        * poppler/Form.cc:
        * poppler/Form.h:
        * poppler/GfxFont.cc:
        * poppler/GfxFont.h:
        * poppler/Makefile.am:
        * poppler/Object.h:
        * poppler/Page.cc:
        * poppler/Page.h:
        * poppler/XRef.cc:
        * poppler/XRef.h:
                Beginning of Interactive Form support:
                Add a bunch of new classes (FormWidget / FormField) to deal with form
                fields.
                Add support for object modification through XRef::setModifiedObject, as
                well as a function to write the Xref to a file, which will be used
                to implement PDF writing.
                Add some functions to glib wrapper to expose the new form features.